Effects of estuarine water mixing on the mobility of trace elements in acid mine drainage leachates

This research reports the effects of pH increase on contaminant mobility in acid mine drainage from the Iberian Pyrite Belt by seawater mixing in the laboratory, simulating the processes occurring in the Estuary of Huelva (SW Iberian Peninsula). Concentrations of Al, Fe, As, Cu and REY in mixing solutions significantly decreased with increasing pH. Schwertmannite precipitation at pH 2.5-4.0 led to the total removal of Fe(III) and As. Subsequently, iron-depleted solutions began to be controlled by precipitation of basaluminite at pH 4.5-6.0, which acted as a sink for Al, Cu and REY. Nevertheless, as the pH rises, schwertmannite becomes unstable and releases back to solution the previously retained As. Moreover, other elements (S, Zn, Cd, Ni and Co) behaved conservatively in mixing solutions with no participation in precipitation processes. Some toxic elements finally end up to the Atlantic Ocean contributing to the total pollutant loads and environmentally threatening the coastal areas.

Bibliographic Details

Main Authors:	Pérez-López, Rafael, Millán-Becerro, Ricardo, Basallote, M. Dolores, Carrero, Sergio, Parviainen, Annika, Freydier, Rémi, Macías, F., Cánovas, Carlos R.
Other Authors:	Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]
Format:	artículo biblioteca
Language:	English
Published:	Elsevier 2023-02
Subjects:	Tinto and Odiel rivers, Contaminants mobility, Estuary of Huelva, Mining pollution, Seawater mixing,
Online Access:	http://hdl.handle.net/10261/289287 https://api.elsevier.com/content/abstract/scopus_id/85147536577
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